Moon-Smashing Probes: Are the Data Worth the Damage?

Anne Minard
for National Geographic News
March 6, 2009
Even as the dust settles from China's deliberate March 1 crash of its Chang'e-1 lunar orbiter, NASA scientists are readying their own moon-smashing probe in the hopes of dislodging lunar ice.

The new NASA mission, set to lift off next month, will advance a decades-long tradition of bullying the moon in the name of science—and some experts are urging extra caution for the future.

Known as the Lunar Crater Observation and Sensing Satellite (LCROSS), NASA's craft will gouge a 100-foot-wide (30-meter-wide) hole in the moon, letting fly 220 tons of material.

Such violent impacts are par for the course—the moon is already littered with more than two dozen landers, orbiters, and rovers launched since the 1960s.

But as the new international space race heats up, there's a growing movement to balance scientific ambition with its possible consequences.

"Any time you crash, obviously you destroy some area of lunar surface for any kind of scientific study, and that's not good," said NASA's lunar sample curator Gary Lofgren. (Read more about NASA's lunar sample collection.)

Last year the International Council for Science's committee on space research imposed new documentation requirements to maintain the credibility of future discoveries on the moon.

"You want to be able to understand what materials you brought with you versus what materials would have been deposited there naturally," said Catharine Conley, NASA's planetary-protection officer.

Merely a Flesh Wound?

The SUV-size Lunar Reconnaissance Orbiter should launch on April 24 and will send LCROSS hurtling into the moon in early August.

The world's telescopes will be watching for the kicked-up debris, and there's a chance amateur astronomers will be able to see the dust cloud with backyard telescopes.

NASA officials say LCROSS is key to the future of lunar exploration. If the probe confirms reservoirs of ice on the moon, those water sources could support bases that might eventually propel humans to Mars and beyond.

As for litter, most of the LCROSS probe will be vaporized on impact, said NASA spokesperson Grey Hautaluoma, and the craft's fuel will be vented prior to impact to avoid contaminating data on the debris cloud.

Worth the Price

According to lunar-sample curator Lofgren, any damages inflicted on the moon so far have been a small price to pay for decades of lunar science.

Currently spacecraft remains occupy only a small portion of the lunar surface, he said.

What's more, meteors usually crash at about 15 miles (25 kilometers) a second, wreaking havoc on the lunar surface. For the most part, human-caused impacts hit at a tenth of that speed.

"They're just going to throw stuff around," he said. "It's not vaporizing materials. It's not melting rocks."

And because the moon has no atmosphere and no wind, the debris won't move around and contaminate other places, he said.

"They're just pieces of metal sitting on the surface."

Planetary protection officer Conley noted that contamination protections for the barren moon—where no known life could survive—will never be as stringent as they are for potentially habitable places like Mars.

NASA's Mars-bound spacecraft are meticulously sterilized, and plans are already being developed for the medical-grade quarantine that will await any Martian samples that could one day return to Earth.

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